A disinfectant for water is a substance that destroys or eliminates infectious or other undesirable bacteria, pathogenic fungi, and viruses in water. Disinfectants kill the growing forms but not necessarily the resistant spore forms of microorganisms. Sanitizers are used to reduce the number of living bacteria in water.
A good disinfectant or biocide program is important for proper performance of a whirlpool spa system, pools, toilets, fountains and the like. Common oxidizing biocides such as chlorine, bromine and chlorine dioxide are routinely used. When properly applied, these compounds are useful for controlling the wide range of microorganisms including bacteria, slime, algae, fungi, and protozoa that prevail in such water systems.
Halogen compounds are usually accepted as the most effective disinfecting or biocidal agents for water systems. They are widely used in pool and spa industries. Typically, it is customary to treat biologically contaminated water with one or more biocides to control the population of microorganisms in the water, to prevent fouling of heat exchanger surfaces, and to prevent the spread of disease. The biocides most commonly used to disinfect and sanitize water in water systems are chemicals that generate various halogen species, e.g. hypochlorite or hypobromide, when dissolved in water. There are many hypochlorite-generating chemicals, but the more common ones are chlorine gas, alkali metal hypochlorites such as sodium hypochlorite, alkaline earth metal hypochlorites such as calcium hypochlorite, chlorinated and brominated hydantoins, and chlorinated isocyanuric acid derivatives.
However, the use as such agents are limited due to, among other things, difficulties in storage, mixing, and handling of concentrated halogens. The use of sodium dichloroisocyanurate as a disinfecting agent is also known as shown in U.S. Pat. Nos. 4,536,389 to White et al. and 5,114,647 to Levesque et al. Sodium dichloroisocyanurate hydrolyses in water to produce hypochlorous acid (HOCl) and hypochlorite (OCl), which exist in solution at an equilibrium that is dependent upon the pH of the solution.
Bromide also has been used as a disinfectant. The hypobromous acid and hypobromite species are produced in solution typically by the use of bromo, chloro-5,5-dimethylhydantoin. One reason why bromine sanitizers have gained popularity for indoor pool and spa applications is that the odor of the bromines, formed by reaction of hypobromite species with nitrogenous wastes, is less objectionable to the consumer. Bromine sanitizers, however, have not been popular for outdoor pools because the hypobromite species are rapidly dissipated in sunlight and the sanitizer costs are considerably higher than chlorine sanitizers with cyanuric acid.
Alternatively, potassium monopersulfate and sodium bromide have been marketed together as a bromine sanitizer system for spa applications. The recommended practice is to dose the spa water with sodium bromide (usually as a solution) and then add the recommended dosages of potassium monopersulfate as needed. However, these suffer from the problem that their use can be cost prohibitive.
The water in swimming pools, hot tubs and spas must be sanitized in order to control disease-spreading microorganisms. The toxicity and odor of compounds used to treat the water must be extremely low.
Therefore, a heretofore-unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.